1. Field of the Invention
The present invention relates to a manufacturing method of a secondary battery, a restraining jig for a secondary battery, a charging/discharging device for a secondary battery, and a charging device for a secondary battery.
2. Description of Related Arts
Recently, a demand for a secondary battery such as nickel hydride battery, lithium ion battery, or the like has been increased with the development of mobile equipment such as cellular phone, portable personal computer, or the like or practicalization of pure electric vehicle or hybrid electric vehicle. During the manufacturing process of a secondary battery, each component is assembled, and then, a battery is activated by performing a charging/discharging to necessarily adjust the characteristic of each battery to a predetermined characteristic. Various types have been proposed for a charging/discharging method after the assembly of the battery and a charging/discharging device used for this (e.g., see Japanese Unexamined Patent Application Publication No. 7-226234(1995), Japanese Unexamined Patent Application Publication No. 2001-291526).
Japanese Unexamined Patent Application Publication No. 7-226234(1995) discloses a charging/discharging device for a cylindrical secondary battery wherein electrodes of the battery and electrode terminals of the charging/discharging device can surely be connected. However, since the internal pressure in the secondary battery increases with the charging, the battery can (battery case) tends to be expanded. In the charging/discharging device disclosed in the publication '234, the battery is repeatedly expanded due to the repeated charging/discharging for the battery, so that stress is repeatedly applied on the battery can (battery case). Therefore, there is a possibility of distortion or deformation produced on the battery can (battery case). Further, the electrolytic solution might be leaked due to the breakdown at the joint section (welding section) of the battery can (battery case).
On the other hand, Japanese Unexamined Patent Application Publication No. 2001-291526 discloses that an expansion restricting member is used, whereby a secondary battery is charged/discharged while restricting the expansion of a battery can (battery case) involved with the charging. Accordingly, it discloses that the deformation of the battery can (battery case) caused by the expansion can be prevented.
However, in Japanese Unexamined Patent Application Publication No. 2001-291526, the expansion restricting member is arranged between each battery after each battery is mounted to a charging jig. Further, in order to transfer the battery, which has been subject to the charging/discharging, to the next process, the expansion restricting member should be removed after the expansion of the battery case is stopped, and further, each battery should be removed from the charging jig. As described above, the technique in the publication '526 brings a troublesome and time-consuming operation before the start of the charging/discharging and after the end thereof (including the waiting time until the expansion of the battery case is stopped), thereby entailing a problem of deteriorating productivity of the secondary battery.